At Salon, Laura Miller cautions about taking book blurbs at face value.

So when publishing people look at the lineup of testimonials on the back of a new hardcover, they don't see hints as to what the book they're holding might be like. Instead, they see evidence of who the author knows, the influence of his or her agent, and which MFA program in creative writing he or she attended. In other words, blurbs are a product of all the stuff people claim to hate about publishing: its cliquishness and insularity.